I would correct the mismatching account types in NV1. Run ATYPE on posting accounts and TATYPE on total accounts. You do not need to run both. Once done, run NVEXPORT again.
They are correct if your Balance Sheet and Income Statement balance with your NV1 books. The errors and warnings are there for you to review and to correct if there are out of balances on a daily basis and if there is a mismatch in references numbers and suspicious dates. If you are in balance and are happy with the results then you can move forward.
No, you are not missing anything. The journals used in NV1 were placed in Journal > General > DOS NewViews Import > Journal Accounts for historical purposes. If you wish to use them, you can. I suggest that you use the NV2 journals instead.